Name: ______
DTEC 110 Powershift Transmission Project
Students will be assigned to a transmission that will be worked on for 2-3 weeks of laboratory.
Each student will: Prior to disassembly in the second week of the project each student will submit answers to the questions listed below in bold.
During the last week of the project, each group will do a presentation for the assigned lab section addressing each of the items listed below.
The transmissions that will be assigned include: Caterpillar Countershaft ZF Countershaft ZF Planetary Komatsu Countershaft Komatsu Planetary
Questions:
1. What is the application for the transmission? 2. Fully describe how the transmission would be operated. 3. How many forward speeds? Reverse speeds? 4. Fully describe the torque converter (operating pressures, lock- up, stator style….) 5. Is the transmission shifted mechanically, hydraulically or electrohydraulically? 6. What are advantages/disadvantages of how the assigned transmission is shifted? 7. Where does the transmission (including the torque converter) receive oil flow from? (Include what drives the pump) 8. Describe the oil flow throughout the transmission when it is in neutral. (include lubrication) 9. Create a chart showing what solenoids are energized and/or clutches are engaged in order to provide all forward and reverse speeds for the transmission. 10. Provide a labeled diagram of the location of each of the clutches are in the transmission. Include what each of the clutches control. 11. List the steps to disassemble the transmission. 12. How is the clutch pack assembled? Transmission specific topics: Caterpillar Countershaft: o How is all-wheel drive accomplished (from the operator’s perspective and inside the transmission? o Where the Transmission Control Valve is located. o How the pressure of the oil in the torque converter is controlled. o How is shifting modulation performed? (Include a colored schematic to show this.) o What controls shifting from 4th forward to 5th forward? How can that be disabled? o What is the function of the neutralizer switch? What does it control in the transmission? o Color individual transmission schematics for the following conditions 1. 1st forward, 2nd forward, 2nd reverse and if the neutralizer button was energized. o Describe the following including a colored schematic showing when the: 1. System is in neutral 2. System is shifted from neutral to 1st 3. System is shifted from neutral to reverse.
ZF Countershaft: o Describe all of the components shown on the power train schematic. o Where the Transmission Control Valve is located. o How the pressure of the oil in the torque converter is controlled. o How is shifting modulation performed? (Include a colored schematic to show this.) o Color an electric schematic for each of the following gears: forward 1, forward 2, forward 5, reverse 1, and reverse 2. o What is the purpose of the WK clutch? What are the electrical inputs? What are the electrical outputs? o What is the purpose of the IG transmitter? How does it function? o Include a colored cutaway of the control valve assembly when the transmission is in forward 3rd.
ZF Planetary: o Is the transmission a “long” or “short” model? o How is shifting modulation performed? (Include a colored schematic to show this.) o What is the purpose of the changeover valve? (include how it functions using a colored schematic) o Where are the valves that control the clutch packs, torque converter and retarder located on the transmission? o How the pressure of the oil in the torque converter is controlled o Describe how the retarder works. (Include a colored schematic if the control switch was switched to 3.) o Color an electrical schematic showing the reverse lights being turned on. o Show the hydraulic flow for Reverse and 3rd forward. (Include a colored schematic.)
Komatsu Countershaft: o Where the Transmission Control Valve is located. o How the pressure of the oil in the torque converter is controlled. o How (and why) the main regulator valve functions as it does o How the quick return valve and accumulator function when: 1. A clutch is engaged, 2. Immediately after gear shifting o How the power modulation functions under each of the five conditions. (include colored hydraulic schematics for each condition) 1. When clutch is completely engaged after the engine starts 2. When transmission is shifted from FORWARD to REVERSE (1st speed). 3. When clutch oil pressure begins raising. 4. When accumulator begins operation. 5. When clutch is fully engaged. o How the accumulator valve functions. o How the clutch cut-off valve functions. o Include a colored cutaway of the transmission for Reverse 2nd.
Komatsu Planetary: o Where the Transmission Control Valve is located. o How the pressure of the oil in the torque converter is controlled. o How (and why) the main regulator valve functions as it does o How the modulating relief valves functions o How the quick return valve functions. o How the reducing valve functions. o Include colored hydraulic schematics for Forward 1st, Forward 2nd, Reverse 2nd and Reverse 3rd. o Explain fully how the modulating relief valve functions (include colored cutaways.) o Explain how the safety valve functions (include colored cutaways) when: 1. Gear shift lever is in neutral 2. Gear shift lever then moved to engage gears 3. When engine is started with the gear lever in any of the speed stages.